In a variety of subterranean environments, submersible pumping systems are used in the production of hydrocarbon based fluids or other types of fluids. A relatively narrow wellbore is drilled, and the pumping system is deployed into the wellbore via, for example, a suspension cable or deployment tubing. Depending on well parameters, the production of fluid, e.g. oil, can be limited by the available horsepower from a given submersible motor or motors used to drive a submersible centrifugal pump. Available horsepower is limited because horsepower generated by the system is transferred through a single shaft to the pump. Due to diameter restrictions, use of a larger shaft to accommodate greater horsepower would require space needed by the centrifugal pump to maintain pumping efficiency.
Sometimes, tandem installations are deployed downhole to increase the production rate. For example, a Y-tool can be used to suspend two electric submersible pumping systems that are offset from each other. However, the offset equipment limits the size of the systems that can be placed into a particular wellbore.